Cloud computing and its applications are effecting a qualitative shift in the way people communicate and share information. The underlying computer networks that support cloud computing can be divided into two major categories: intra-datacenter and inter-datacenter. Intra-datacenter network interconnects the computing infrastructure (servers, disks) within the same building or among different buildings of a datacenter campus; while inter-datacenter network refers to connections from metropolitan to long-haul reach interconnecting multiple datacenters distributed at different geographic locations. Many modern high-speed data links use optical transmission technologies via optical fibers for both intra- and inter-datacenter networks.
Today, most of the actual computing and storage underlying the Internet and cloud computing takes place in warehouse-scale data center buildings. Similarly, most of the long-haul links transferring data and requests back and forth between end users and data centers are switched through Internet points of presence (POP). Both environments must transfer a tremendous amount of data between individual computers and the switches and routers responsible for getting the data to its destination. Current data centers contain predetermined topology structures for switching and interconnecting Internet data to determine a given destination.